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To date, the United States
has confirmed a total of 109 human cases of swine influenza A H1N1: 1
in Arizona, 14 in California, 1 in Indiana, 2 in Kansas, 2 in
Massachusetts, 1 in Michigan, 1 in Nevada, 50 in New York City, 1 in
Ohio, 10 in South Carolina and 26 in Texas. Other suspected cases are
being investigated. 5 hospitalizations and a death have been
registered. The dead case is a child of 22 months old, from Mexico who
died in a hospital of Houston, Texas area.

The most recent cases detected as well as the registered death
suggest that more serious cases could appear in the United States.

From 17 to 29 April, Mexico has reported 1,918
suspected cases of influenza with severe pneumonia including 84 deaths.
The suspected cases were recorded in all Mexican states. Most of them
in the Federal District, Guanajuato, State of Mexico, Aguascalientes,
Queretaro and San Luis Potosí. The majority of these have occurred in
previously healthy young adult people. There have been few cases in
individuals under 3 or over 59 years old. 933 of the suspected cases
are currently hospitalized.

The number of probable cases of swine influenza A H1N1 remains at
286, and a total of 97 cases has been confirmed. The considerable
variation in the number of confirmed cases as of today is due to the
recent laboratory confirmation of samples collected in previous weeks.
The number of confirmed dead cases remains at 7. This figure is also
subject to variations depending on the new laboratory information.

In Canada, to date 19 human cases of swine
influenza A H1N1 have been confirmed (2 in Alberta, 4 in the province
of New Scotland, 6 in British Columbia and 7 in Ontario) some of them
with recent trip history to Cancun, Mexico. All the cases developed a
mild form of influenza like illness. 2 of the cases presented, in
addition, gastrointestinal symptoms. All of them are currently
recovered and none required hospitalization. Laboratory tests were
conducted in Winnipeg, Canada. `Indigenous` transmission is not
discarded since not all the confirmed cases have trip history to Mexico.

The press has reported information on suspected cases in several
countries of the Region; however this information has not been
confirmed.

International Health Regulations (IHR)

At the request of the Director-General (DG) of WHO, the IHR
Emergence Committee has been summoned and is advising the DG on the
event. On its first day of deliberation, 25 April, it concluded that
the present event constitutes a Public Health Emergency of International Concern.

On 29 April 2009, the DG decided to elevate the pandemic alert to
Phase 5. In order to come to this urgent decision, the DG considered
epidemiological information from the most affected countries, as well
as the result of the scientific meeting held that same day. The latter
indicated existence of sustained outbreaks of swine influenza A H1N1 at
the community level in more countries within the Region.

The decision to increase the pandemic level of the alert should
permit Member States to provide the required leadership and
coordination as well as to consider the possibility of executing their
contingency plans.

The DG recommends not closing borders or restricting travel.
However, it is prudent for people who are sick to delay travel.
Moreover, returning travelers who have become sick should seek medical
attention in line with guidance from national authorities.

Production of seasonal vaccine should continue, but at the same
time, WHO is making all the efforts to facilitate the process of
development of a vaccine against swine influenza A H1N1.
The Committee will continue to advise the DG on the basis of the available information.

Recommendations

Enhanced surveillance

At this time, enhanced surveillance is recommended. On its Web page,
PAHO has published orientations for the enhancement of surveillance
activities, which are directed to the investigation of:

Clusters of cases of ILI/SARI of unknown cause

Severe respiratory disease occurring in one or more health workers

Changes in the epidemiology of mortality associated with ILI/SARI;
increase of observed deaths by respiratory diseases; or increase of the
emergence of severe respiratory disease in previously healthy
adults/adolescents.

Persistent changes observed in the response to the treatment or evolution of a SARI.
The following risk factors should also cause suspicion of swine influenza A H1N1 virus:

Close contact with a confirmed case of swine influenza A H1N1 while the case was sick.

Recent travel to an area where there are confirmed cases of swine influenza A H1N1 have been confirmed

Virological surveillance of swine influenza A H1NI

It is recommended that National Influenza Centers (NIC) immediately
submit to the WHO Collaborating Center for influenza (CDC of the United
States) all positive but unsubtypable specimens of influenza A.
Shipment procedures are the same as those used by NICs for seasonal
influenza specimens.

The test protocols for the detection of seasonal influenza by
Polymerase Chain Reaction (PCR) cannot confirm swine influenza A H1N1
cases. The Centers for Disease Control and Prevention of the United
Sates are preparing testing kits that will include the primers and
probes as well as the required positive control samples. The kits will
be sent in the first week of May to those NICs that currently use the
CDC protocol.

Infection prevention and control in health care facilities

Since the main form of transmission of this disease is by droplets
it is recommended strengthening the basic precautions to prevent their
dissemination, for example the hygiene of hands, adequate triage in the
health facilities, environmental controls, and the rational use of the
personal protective equipment in accordance with the local regulations.